By 
Part of: Divorce Specialists
Can you marry your cousin in the UK? In England and Wales, and in Scotland, yes. Cousins are not on the legal list of relatives you cannot marry, and that includes first cousins. The list sits in Schedule 1 to the Marriage Act 1949, and a marriage to someone on its main list is void. A Bill that would stop first cousins marrying is now before Parliament, but it is not law. Our divorce specialists assist and advise on marriage and divorce law in England and Wales.
This guide covers England and Wales, with a note on Scotland: who you cannot marry, where the First Cousins (Prohibited Relationships) Bill stands, and what to check before you give notice.
Reviewed by: Iblal Iqbal, Partner & Family Law Strategist, Kabir Family Law
Key takeaways
- Cousins can marry today. First cousins, second cousins and cousins once removed are all missing from the list of relatives you cannot marry (Marriage Act 1949, Sch. 1).
- A ban is a proposal, not the law. The First Cousins (Prohibited Relationships) Bill had its first reading on 17 June 2026, and Parliament lists its second reading for 15 January 2027 (UK Parliament).
- The law bars close relatives. You cannot marry a parent, child, grandparent, grandchild, brother or sister (half-siblings included), aunt, uncle, niece or nephew.
- You must both be 18 or over. A marriage where either of you is under 18 is void (Marriage Act 1949, s.2).
- Pressure to marry is a crime. Using threats or any other coercion to make someone marry is a criminal offence (Anti-social Behaviour, Crime and Policing Act 2014, s.121).
Is it legal to marry your cousin in the UK?
In England and Wales, yes. The law names the relatives you cannot marry, and cousins are not among them, so cousins can marry each other. They can also form a civil partnership, which uses the same list (Civil Partnership Act 2004, Sch. 1).
The usual rules still apply when cousins marry. According to GOV.UK, you must both be 18 or over, not already married or in a civil partnership, and not closely related. You must also give notice at a register office at least 29 days before the ceremony. Our guide to the legal age for marriage explains the age rule.
Scotland has its own list, in the Marriage (Scotland) Act 1977, and cousins are not on it either. Northern Ireland has separate marriage rules, which this guide does not cover.
Can you marry your first cousin in the UK?
Yes. A first cousin is the child of your aunt or uncle, so the two of you share a set of grandparents. Nothing in the law of England and Wales stops first cousins from marrying. The same goes for second cousins, who share great-grandparents, and for cousins once removed.
Half relationships can trip families up. The list treats a half-sibling as a sibling, so your parent’s half-brother or half-sister counts as your aunt or uncle, and you cannot marry them. In a blended family, someone everyone calls a cousin can turn out to be a half-aunt or half-uncle. Before you plan to marry your cousin, be sure of the exact family link between you.
What is the First Cousins (Prohibited Relationships) Bill?
It is a Private Members’ Bill from Dr Luke Evans MP, which started in the House of Commons in the 2026-27 session. Its long title says it would “prohibit the marriage of first cousins”, and it would also ban civil partnerships and sexual activity between first cousins (UK Parliament).
It is a ballot bill, the type Parliament says is most likely to become law, because it gets priority for debating time (UK Parliament). Even so, it must pass every stage in both Houses and receive Royal Assent.
An earlier attempt to stop cousins marrying, the Marriage (Prohibited Degrees of Relationship) Bill, had its first reading on 10 December 2024. However, it never had a second reading and did not become law.
Where does the Bill stand today?
The Bill has passed one stage, a first reading in the House of Commons on 17 June 2026, which is a formal step with no debate. Next comes the second reading, the first chance for MPs to debate its main principles. Parliament lists it for 15 January 2027 but warns that future dates may be provisional.
Parliament has not published any text of the Bill yet, so nobody can say exactly how it would work. Even after Royal Assent, a new Act can start later, sometimes only through a commencement order (UK Parliament). Look at the Bill’s stages page before you give notice.
The law today
Cousins can marry in England and Wales.
- First and second cousins are not on the list
- Civil partnerships follow the same list
- Usual age and notice rules still apply
What the Bill proposes
A ban on first cousins marrying, if it ever becomes law.
- First reading: 17 June 2026
- Second reading listed for 15 January 2027
- No Bill text published yet
Would a ban affect cousins who have already married?
Without a published text, nobody can say whether a ban would reach only future marriages, or how it would treat cousins who married abroad. If you have already married a cousin, keep an eye on the Bill rather than acting in a hurry.
Who can’t you marry in England and Wales?
The list covers close blood relatives, some adoptive relatives and, with conditions, some step-relatives.
| Relationship | Can you marry them? | Where the rule comes from |
|---|---|---|
| First cousin | Yes | Not on the list in Schedule 1 |
| Second cousin or cousin once removed | Yes | Not on the list in Schedule 1 |
| Step-cousin | Yes | Not on the list in Schedule 1 |
| Aunt, uncle, niece or nephew, including half relations | No, the marriage is void | Schedule 1, Part 1 |
| Brother, sister, half-brother or half-sister | No, the marriage is void | Schedule 1, Part 1 |
| Parent, child, grandparent or grandchild, including an adoptive parent or child | No, the marriage is void | Schedule 1, Part 1 |
| Stepchild, step-parent or step-grandparent | Only if you are both 21 or over, and the younger one was never a child of the older one’s family before turning 18 | Schedule 1, Part 2, and section 1(3) |
Adoptive links need care too, because the list names an adoptive parent and child but not every adoptive relative.
What happens if you marry someone the law says you cannot marry?
The marriage is void. The Matrimonial Causes Act 1973, s.11 says so for people within the prohibited degrees of relationship. It also covers a party under 18 and some breaches of the rules for forming a marriage.
You can still ask the court for a nullity of marriage order, and the court can then make financial orders, much as it can on divorce (Matrimonial Causes Act 1973, s.23). Our guide to marriage annulment explains that process. None of it touches cousins, who can marry.
Does marrying your cousin abroad count in the UK?
Being cousins is not, on its own, a reason for a marriage to fail under the law of England and Wales. But if you marry your cousin abroad, other rules come in. The marriage can depend on the law of the country where it took place, and on each person’s domicile, a legal idea linked to your permanent home (Matrimonial Causes Act 1973, s.14).
If there is doubt, you can ask the High Court or the family court to declare whether a marriage was valid from the start, as long as one of you has a strong enough link to England and Wales (Family Law Act 1986, s.55). Our international family law specialists assist and advise on marriages that cross borders.
Marrying your cousin in a religious ceremony: is it legally binding?
Only if it also meets the legal rules. GOV.UK explains that a religious wedding can take place at any registered religious building, with an authorised person, such as a religious minister, there to sign the marriage schedule. You can also hold a civil ceremony and have a religious blessing afterwards.
The risk sits with ceremonies that happen outside those rules. The Court of Appeal has held that some ceremonies do not create a marriage at all, not even a void one. Such a ceremony gives no separate legal rights, so there is no nullity route to financial orders if the relationship ends (Akhter [2020] EWCA Civ 122, paras 6 and 121).
This applies to every faith, not just to cousins. If you plan to marry your cousin in a religious ceremony, settle how the law will treat it well before the day.
What if someone feels pressured to marry a cousin?
Everyone has the right to choose whether, when and who they marry (GOV.UK). Using violence, threats or any other coercion to make someone marry is a criminal offence in England and Wales. Doing anything to make a child marry before their 18th birthday is also an offence, even without pressure (s.121).
Nobody should have to marry a cousin, or anyone else, against their will. If you or someone you know is in danger, call 999. The Forced Marriage Unit gives free advice on 020 7008 0151, Monday to Friday, 9am to 5pm, or 020 7008 5000 out of hours. A court can also make a forced marriage protection order to protect someone at risk (Family Law Act 1996, s.63A).
Planning to marry a cousin? Are your plans on track?
This quick check shows where you stand. It is not a test, and it cannot tell you whether your marriage will be valid.
There is no score. Anything you cannot tick yet is worth raising before you give notice or book a ceremony.
The calls a checklist can’t make for you
- Whether a ceremony abroad, or a religious-only ceremony, would give you a valid marriage here.
- Whether a half, step or adoptive link puts either of you on the list of relatives who cannot marry.
- What the First Cousins Bill could mean for your plans once Parliament publishes its text.
- What to do if anyone in the family feels pressure to marry.
These turn on your own facts, and they are far easier to settle before the ceremony.
Book a free initial consultation
One of our specialists will give you initial advice on your situation.
Frequently asked questions
Can a brother and sister marry in the UK?
No. In England and Wales, brothers, sisters, half-brothers and half-sisters are all on the list, so any such marriage is void. Scotland’s list also includes siblings, whether they share one parent or both.
Can you have a child with your cousin?
The law does not stop you. The criminal offence of sex with an adult relative covers close relatives such as parents, siblings, aunts and uncles, but not cousins (Sexual Offences Act 2003, s.64). The First Cousins Bill would change this for first cousins if it became law. For health questions, the NHS suggests talking to your doctor about genetic testing.
Is it legal to marry your second cousin in the UK?
Yes, in England and Wales and in Scotland. Second cousins are not on either list. Going by its long title, the First Cousins Bill targets first cousins only, although Parliament has not published its full text.
Has the UK banned cousins from marrying?
No. In England and Wales, cousins can still marry. The First Cousins (Prohibited Relationships) Bill would ban marriage between first cousins, but it has only had its first reading. To become law, it must pass every stage in both Houses and receive Royal Assent.
Can you marry your cousin in Scotland?
Yes. Cousins are not on Scotland’s own list, in the Marriage (Scotland) Act 1977, and Scottish law says a relationship missing from that list does not stop a valid marriage.
Does religious law change the position in England and Wales?
No. A faith’s rules can matter a great deal to a family, but they do not change the legal list of relatives or the rules for forming a valid marriage in England and Wales.
Planning a cousin marriage? Check where the law stands before you give notice
The Bill could change the rules, a marriage abroad can turn on more than one country’s law, and a ceremony that misses the legal rules may not make you married at all. All three are far harder to fix after the day. Book a free initial consultation and one of our specialists will give you initial advice tailored to your circumstances. You can also read about our divorce specialists.
General information about the law in England and Wales, not advice on your circumstances.
Expert Tip
People often ask us whether the law allows a marriage to a cousin, which is usually the simple part. The harder questions are how and where you marry. A ceremony abroad, or a religious ceremony that misses the legal rules, can leave one of you without the protection a valid marriage gives if the relationship ends. Before you give notice or book a venue, get advice on how the law will treat your ceremony, and look at where the First Cousins Bill stands.
Garry Steedman, Family Law Consultant (Divorce, Children & TOLATA)
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